Masks of cancers in the practice of an infectious disease doctor

The purpose of this work is to remind doctors practical medicine about the importance differential diagnosis with cancers in general pediatric practice and increase vigilance clinicians regarding similarity manifestations oncology infectious diseases on example specific clinical cases. We conducted an empirical, descriptive study 4 cases children. selected them among 21 patients who were diagnosed cancer during inpatient treatment at Kyiv City Children’s Infectious Disease Hospital 2014–2019. first case describes a brain neoplasm that was initially thought be acute VZV encephalitis 11-year-old child. second leukemia 3-year-old child hospitalized suspected meningococcal infection. In third case, we presented 7-year-old patient admitted mononucleosis as result, hemophagocytic syndrome, immunodeficiency Duncan disease. latest demonstrates combination tuberculous meningitis cerebral astrocytoma 15-year-old patient, which mistaken for viral encephalitis. Conclusions. Awareness important nosologies. Dynamic monitoring use wide range laboratory instrumental methods allows prevent diagnostic errors seek timely manner.